1. Field of the Invention
The present disclosure relates to power converters, and more particularly to rectifiers for converting alternating current (AC) power into direct current (DC) power.
2. Description of Related Art
Rectifiers are commonly employed in aerospace, marine, and terrestrial vehicles, electrical power networks and systems, variable speed drives, grid interfaces for renewable energy sources, electrical energy storage systems, and telecommunications systems to convert alternating current (AC) power into direct current (DC) power. Rectifiers can include solid-state devices such as diodes, metal oxide field effect transistors (MOSFETs), insulated gate bipolar transistors (IGBTs), or gate turn-off device (GTOs) arranged between an AC power source and a DC load. Such solid-state devices typically have electrical stress limits that determine the maximum output power that a rectifier can reliably provide. Since the need of some rectifier applications can exceed the rating of such solid-state devices, some rectifiers employ the devices in a multilevel topology. Such topologies generally include numbers of solid-state devices that scale with the number of voltage levels in the topology, one exemplary N-level topology including N−1 capacitors and 2(N−1) solid-state switch devices clamped by diodes for each voltage level. Conventional topologies can also require voltage balancing circuitry to control and balance the DC link capacitor voltages, potentially reducing the power density, efficiency and reliability of such rectifiers.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved multilevel rectifiers. There is also a continuing need for rectifiers with greater power density, reliability, and efficiency. The present disclosure provides a solution for this need.